Electric switch



April 20, 1937. G. J. MEUER 2,077,577

` ELECTRIC SWITCH Original Filed Nov. 9, 1934 2 Sheets-Sheet 1INSULATION INSULATIONJ @MMM/f April 20, 1937. G. J. MEUER 2,077,577

ELECTRIC SWITCH Original Filed Nov. 9, 1954 2 Sheets-Sheet 2 a9 '7l e5sa 84 aa vz 87 ,la 7 740 O 75 9' 76 9 73 73 LIQLIIIIJL- 9] l 77 78 l A95 80 n 9a A I INSULATIoN 98 97 94 96 95 9! Patented Apr. 20, 1937UNITED STATES PATENT OFFICE ELECTRIC SWITCH George J. Mener,

Cutler-Hammer, Inc., poration of Delaware Milwaukee, Wis., assigner toMilwaukee, Wis., a cor- 1936, Serial No. 72,581

9 Claims.

This invention relates to improvements in electric switches, and theinvention relates more particularly to improvements in electric snapswitches of the tool-handle type.

A primary object of the invention is to provide novel means forrelieving pulling strains upon the end-wiring terminals of switches ofthe aforementioned character.

Another and more specific object is to provide a strain relief device inthe form of an attachment for switches of known construction.

Another object is to provide a novel form of pivotal support for theswitch actuating lever.

Another object is to provide a novel form of mounting means for themetal top plates of switches of the aforementioned character.

Another object is to provide an electric snap switch having a novel formoi connection between the contacter and its carrier.

Another object is to provide an improved form of wiring terminal clamp.

Another object is to generally improve the details of construction,assembly and operation of the parts of switches of the aforementionedcharacter.

Other objects and advantages of the invention will hereinafter appear.

This application is a division of my copending application, Serial No.752,202, led November 9, 1934, for improvements in electric switches.

The accompanying drawings illustrate certain embodiments of theinventionA which will now be described, it being understood that theembodiments illustrated are susceptible of modication as to certaindetails oi construction thereof without departing from the scope of theappended claims.

The snap switches herein disclosed are in general of the characterdescribed and claimed in my prior patents, No. 1,889,259, dated Nov. 29,1933, and No. 1,977,078, dated Oct. 16 1934, to which patents referencemay be had for a more detailed description of certain elements of theswitch mechanism.

In the drawings, Figure 1 is a vertical sectional view of an electricalsnap switch of the end-wiring type, having my improved form of wiringterminal strain-relief applied thereto.

Fig. 2 is an end view of the switch illustrated 50 in Fig. 1.

Fig. 3 is a bottom plan view of the switch shown in Figs. 1 and 2.

Fig. 4 is a perspective view oi a modified form of strain-relief plate,which may be substituted 55 lor that shown in Figs. 1. 2. and 3.

(Cl. 20o-57) Fig. 5 is a bottom plan view of a switch like that shown inFigs. 1 and 2, but having a modifled form of strain-relief plate of thecharacter best illustrated in Figs. 6 and 7.

Fig. 6 is a fragmentary end view oi a switch, with the strain-reliefplate shown in section to illustrate the manner of inserting thestraight bared ends of the circuit wires.

Fig. 7 is a perspective view of the strain-relief plate shown in Figs. 5and 6.

Fig. 8 is a top plan view of a switch, with certain of the actuatingelements removed, and showing a type of wiring requiring a strain-reliefplate of the character illustrated in Figs. 1 to 3 or Fig. 4.

Fig. 9 is a vertical sectional view of a moded form of switch embodyingcertain novel detalls of my invention, including a novel form ofstrainrellef for the wiring terminal members.

Fig. 10 is a view, partly in end elevation and partly in verticalsection, of the switch shown in Fig. 9, and

Fig. 1l is a fragmentary top switch shown in Figs. 9 and 10, with theing and metal top plates omitted.

Referring first to Figs. 1 to 3, the numeral I5 designates an insulatingbase which is preferably molded from a phenol formaldehyde condensationproduct. Said base is recessed from its upper surface to provide achamber in which are located two pairs of resilient contacts I6, I1 andI8, I9, the tips of which contacts are biased toward each other, as bestillustrated in Fig. 1. Interposed between the respective pairs ofcontact tips at all times is a iiat punched plate 2li of insulation,said plate being slidable over the iiat upper surface 2| of a rib formedupon the bottom wall of said chamber. Plate 2li is notched at oppositeside edges thereof to receive a pair of U-shaped contactors 22 and 23,the arms of each contactor being exposed on opposite sides of saidplate. In one extreme position of plate' 2li the contactors carriedthereby are moved into bridging engagement with the respective pairs ofcontact tips (Figs. 1 and 8), and in the other extreme position of saidplate the contactors are disengaged from said contacts.

Superimposed upon plate 20 is a relatively smaller punched plate 2l ofinsulation, said plates '24 and 22 having registering openings ofrectangular contour to receive with a close fit the reduced lower end ofa flat punched sheet metal member 25, said reduced lower end being upsetover the lower surface of plate 22 to secure said parts to each other.The switch actuating plan view of the lnsmatf mechanism preferablycomprises a wire member 26 of substantially w-form (as shown in detailin my Patent No. 1,977,078), said member being pivotally supported at 21and 28 by the bulged portion 29 of top plate 28.

Secured to top plate 29 in a well known manner is an externally threadedyellow metal bushing Ill, said bushing having aiined openings formedtherein to receive a pivot pin 3l. Pin 3| is provided with a slightlyenlarged intermediate portion (not shown) to provide for a drive i'ltthereof in an opening formed in the flat punched sheet metal actuatinglever 32, said lever being of the desired length and having a ball orknob attached thereto with a drive fit, as indicated in the levers ofFigs. 9 and l0. 'I'he upper closed end of bushing I0 is provided with akerf to permit oscillatory movement of lever 32.

A coiled compression spring 33 is engaged at its lower end with member26, the upper end of said spring being provided with a metal cup memberto receive an abutment formed at the lower end of lever 32. A relativelythin punched insulating member 34 is interposed between the member 26and the stationary and movable contact elements of the switch toproperly insulate the latter from the former, said member 34 having aslot (not shown) formed therein to provide clearance for member 25. Alsoas will be apparent, the provision of insulating plate `2l insures arelatively large linear distance between the stationary and movableswitch contacts and the member 25, thus increasing the current makingand breaking capacity of the switch.

Top plate 29 is secured to base Il as by means of a pair of screws theshanks of which are shown at 35 and 3B, the heads of said screws beinglocated in countersunk recesses in the bottom surface of said base, asshown in my patents aforementioned. The respective stationary contactsof the switch are attached to base l5 at the four corners of the latterand in a plane oil'set downwardly from the upper surface of said base,es by means of eyelets 31, 3B, I9, and III. Said eyelets also act tosecure in position the horizontal portions Il, l2, 43, and Il of theend-wiring terminal members of the switch, said members having dependingvertical portions which are adapted to abut against shoulders formed onthe respective ends of the base II to prevent inward bending oi' saidvertical portions as an incident to tightening of the respective bindingscrews. Binding screws ll, 4i, Il, and I8 are located adjacent to thelower ends of the vertical portions of the terminal members. and base l5is provided with recesses to afford clearance for the shanks of saidscrews. A flat punched plate l! of insulation is interposed between theupper surface of base l5 and top plate 29 to properly insulate thelatter from the aforementioned wiring members.

In wiring a switch of the character herein described it is frequentlynecessary or desirable to employ relatively large gage solid wires ofthe character illustrated, whereas upon bending of said wires or uponpulling of the same (or any type of wire) endwise of base i5 anundesirable strain is placed upon the vertical portions of the wiringterminal members, with resultant liability of outward bending ordistortion of the latter. To overcome this difficulty in a simple andeconomical manner, I provide a at punched insulating plate B0 which isprovided with a D pair of relatively large substantially circularopenings adjacent to each end thereof, said openings being designated bythe numerals 5|, 52, 53, and Il. 'I'he arrangement of said openings ispreferably such that upon seating of plate In against the lower surfaceof base I5. the circularly looped ends` of the wires may be insertedupwardly through the respective openings at a suilicient outward angleto clear the lower end of base I5 and the lower extremities of theterminal members. The wire ends are then positioned vertically as shownin full lines in Figs. 1 and 2 to bring the respective loops inalinement with the tapped openings in said terminal members. Theaforementioned binding screws are then applied to mechanically andelectrically connect the wire ends to the terminal members.

If the wire ends are bared to the proper length, the shoulders formed bythe ends of the respective wire sheaths will act to restrain plate Illagainst vertical displacement. In ordinary usage. however, it isdesirable to provide a substantially right angled bend in each wire, asshown in dotted lines in Fig. l. In order to prevent endwisedisplacement of plate lll relatively to base I! I prefer to provide theformer with an opening 65 to accommodate a substantially rectangularprojection Il* formed on the lower surface of said base. Thus uponbending of the several wires in the manner indicated in dotted lines inFig. l the outer edges of the respective openings` Il to M will act assnubbing shoulders to prevent transmission to the terminal members ofany bending or outward pulling strains upon the wires, the interlockbetween plate S0 and projection II' assisting in the performance of thisfunction. Moreover, it will be apparent that outward bending of theseveral wires will serve to securely clamp plate Il against the bottomsurface of base II.

'I'he modified form of wiring terminal strainrelief plate SII* shown inFig. 4 is provided with the aforedescribed openings M to 54, inclusive,and the same is additionally provided with a pair of openings 66 and 51which are adapated to receive the shanks of a pair of securing screws(not shown) which are relatively longer than the screws 3l and I8aforementioned. The heads of said longer screws are adapted to engagethe lower surface or plate l0 to provide for factory assembly thereofwhereby the same is retained in seated position against the lowersurface of base Il independently of the circuit wires.

In Figs. 5, 6, and 7 I have shown a wiring terminal strain-relief plateIl which is provided with openings 5l. Il and l1 like those shown inFig. 4. However. plate il is provided with two pairs Il, Il, Il, and 82of relatively small circular openings, which pairs are offset inwardlyfrom diagonally opposite corners of the plate. Said openings are justsumciently large to provide for upward insertion of the straight baredends of the respective circuit wires 8l, M, il, and O6. and saidopenings are so arranged as to insure positioning of the wire ends atthe left-hand sides of the respective screw shanks (Fig. 6). With thisarrangement the binding screws need not be entirely removed from theterminal members to permit insertion of the wire ends, whereas upontightening of the screws the wire ends are secure ly clamped by thescrew heads in mechanical and electrical contact with the respectiveterminal members.

The walls of the respective openings Il to l2. inclusive. serve assnubbing shoulders upon bending o f the several wires in the mannerindicated in dotted lines in Fig. 1, whereby the downwardly extendingportions of the several terminal members are relieved of outward bendingstrains as an incident to an outward pull upon the circuit wires. Asaforeindicated, the opening 55 in plate 58 is adapted to accommodate theprojection l5 on the bottom surface of base l5. It is to be understood,oi course, that the shorter length screws 35 and 35 oi Figs. 1 and 2 maybe substituted for the screws 51 and 58 in Figs. 5 and 6, to provide forsupport of plate 58 solely by the circuit wires upon bending of thelatter. the walls of opening 55 cooperating with projection lis in suchcase to prevent displacement of plate 5B longitudinally of base I5.

The switch illustrated in Figs. 9, 10, and 11 is in general like thatshown in Figs. 1 to 8. However, the switch of Figs. 9 to l1 is of suchsize and construction as to have a rated capacity of 10 amperes at 250volts or 15 amperes at 125 volts, whereas the switch of Figs. 1 to 8 hasa rated capacity of 5 amperes at 259 volts. It is to be understood, ofcourse, that certain features of each oi these two types of switches maybe utilized in the construction of the other type of switcri. Forexample, the top plate of inverted channelshape and the actuating levershown in Figs. 9 and 10 may be employed without change in conjunctionwith a molded base and other parts of the size shown in Figs. l to 8 toprovide a switch of the aforementioned lower current-controllingcapacity.

Certain of the parts of the switch illustrated in Figs. 9, 10, and 11are shown and described in detail in Figs. 1 and 2 of my Patent No.1,977,078. Thus I provide a metal top plate 69 of invertedchannel-shape, which is secured to the molded insulating base 10 as bymeans of screws 1l and 12. A iiat punched plate 13 of insulatingmaterial is interposed between the base 10 and the bottom flanges of thetop plate 69.

Each of said pair of ilanges is provided with a pair of downwardlyextruded bosses, one pair being shown at 14 and 15 and one boss of theother pair being shown at 16; and the plate 13 is provided with recesses11, 18, and 19 to snugly receive said bosses. Although I have shown saidrecesses as comprising openings extending through plate 13, it is to beunderstood that the recesses may be formed by locally compressing theplate without eiiecting penetration thereof. The arrangement justdescribed insures against outward sliding of said flanges and consequentspreading of the substantially parallel sides of the top plate in theevent of excessive tightening of screws 1I and 12. A proper pivotalsupport for the outwardly bent ends of the U-shaped yoke member B0 isthus provided.

The flat punched sheet metal actuating lever 8l is preferably providedwith integral lugs having downwardly angled edges 82 and 83 which extendin the plane of said lever beyond the opposite ends of the slot 84 inthe upper portion of top plate 59 to thereby limit the degree ofoscillation ci lever Bi in each direction.

As best illustrated in Fig. l0, top plate 59 is provided with a pair ofalined pivot openings 85 and 85, and lever 8l is provided with arelatively smaller opening alined with said pivot openings. A pivot pinis provided with a portion B1 of relatively large diameter and a portion88 of relatively small diameter, said pin being freely insertableendwise through the several openings in such manner that said shoulderabuts one side of lever 8l, and the portion 81 has bearing, engagementwith opening 56. A metal tube or errule 80 is slidable onto the smalldiameter port on 8B of the pin to provide a shoulder abutting the otherside of lever BI. The hollow outer end of portion 89 is upset as shownto retain all of said parts in assembled relation, it being noted thati'errule 89 has bearing engagement with opening 85.

The aforementioned upsetting operation is such that a clamping action ofthe inner end of the ferrule against lever 8l is effected to preventrelative movement of the lever and the pin, wherefore the pivotingaction takes place solely between the pivot pin and its bearings B5 and86. By the arrangement just described I am enabled to provide a veryclose and accurate fit of the pin within its bearings, and this feature,in conjunction with the fact that slot 84 is only slightly wider thanthe thickness of lever 8l, insures against undesirable looseness orlateral wobbling of said lever.

The base 10 as shown is provided with pairs of vertical slots or grooves90, into which pairs of grooves the vertical portions of the respectiveterminal members 9| are insertable downwardly prior to securementthereof by the eyelets or rivets 9|. Said terminal members 9i are ofcourse positioned prior to insertion of the respective binding screws92; although if desired the screws might be partly threaded into thetapped openings in the terminal members prior to attachment thereof tobase 10. The Walls of the aforementioned pairs of grooves 9|! act toprevent inward bending of the terminal members upon tightening of therespective binding screws, and said walls likewise act to preventoutward bending or distortion of the terminal members in the event of anoutward pull upon the circuit wires. If additional resistance to outwardbending strains upon the terminal members is desired, one of the severaltypes of strain relief plates of the character described in connectionwith Figs. 1 to 8 may of course be employed.

Where straight bared ends of the circuit wires are attached to theterminal members 9| by the binding screws, as shown in Figs. 9, 10, and11, I prefer to employ a thin metal clamping plate 93 in conjunctionwith each terminal member, said plates each having the vertical edgesthereof bent inwardly toward the respective terminal member to guide thecircuit wire toward and retain the same adjacent to the shank of thescrew, whereby proper clamping thereof by the screw head is insured.Each plate is also provided with an opening (Fig. 9) to provideclearance for the shank of its associated binding screw. As indicated inFig. 1l, the use of clamping plates 93 will facilitate proper attachmentof a pair of bared wire ends to any or all of the respective terminalmembers, Where such circuit connections are necessary or desirable.

The flat punched plate 94 of insulating material is slidable over thefiat upper surface 95 of the rib formed on the bottom wall of thecontact chamber. One of the U-shaped contactors carried by plate 94 isshown in section at 96 in Fig. 9; and as shown I prefer to rigidlyattach the arms of each contacter to the respective sides 0f said plateas by means of a rivet or eyelet 91 which penetrates alined openingsprovided in said arms and in plate 94. One pair of lower and upperstationary contacts is designated by the numerals 98 and 99. Theprovision of rivets 91 additionally insures a good electrical connectionbetween the arms of the contactor even though the integral connectingportion thereof should be burned or worn away during use of the switch.

What I claim as new and desire to secure by 5 Letters Patent is:

1. In an electric snap switch, in combination,

a punched and stamped sheet metal top plate of substantially invertedchannel-shape, said top plate having alined bearing openings formed l0in the opposite parallel sides thereof, said plate having a. relativelynarrow rectangular slot formed in the upper portion thereof, a atpunched sheet metal actuating lever insertable within said slot andrestrained by the latter against movement laterally of said plate, `saidlever having a pivot opening formed therein, a pivot pin having aportion of relatively small diameter and a portion of relatively largediameter with a shoulder therebetween, said pin being freely insertableendwise through said bearing openings and the small diameter portionthereof being adapted to freely penetrate the pivot opening in saidlever, whereby said shoulder is engaged with one side of said lever, aferrule slidable onto said pin portion of small diameter and adapted toprovide a shoulder which is engaged with the other side of said lever,said portion of relatively large diameter being adapted to engage with asnug fit one of said bearing openings andsaid ferrule being adapted toengage with a snug fit the other of said bearing openings, and the endof said small diameter portion being upset to retain all of said partsin assembled relation.

2. In an electric snap switch, in combination, a punched and stampedsheet metal top plate of substantially inverted channel-shape, said topplate having alined bearing openings formed in the opposite parallelsides thereof, said plate having a relatively narrow rectangular slotformed in the upper portion thereof, a fiat punched sheet metalactuating lever insertable within said slot and restrained by the latteragainst movement laterally of said plate, said lever having a pivotopening formed therein, a pivot pin having a portion of relatively smalldiameter and a portion of relatively large diameter with a shouldertherebetween, said pin being freely insertable endwise through saidbearing openings and the 5o small diameter portion thereof being adaptedto freely penetrate the pivot opening in said lever, whereby said,shoulder is engaged with one side of said lever, a ferrule slidable ontosaid pin portion of small diameter and adapted to provide a shoulderwhich is engaged with the other side of said lever, said portion ofrelatively large diameter being adapted to engage with a snug fit one oisaid bearing openings and said ferrule being adapted to engage with asnug llt the other of said bearing openings, the end of said smalldiameter portion being upset to retain all of said parts in assembledrelation, and said lever having integral lugs with downwardly` anglededges ar ranged on opposite sides of said pivot opening,

said lugs being respectively engageable with the inner surface of saidchannel member beyond opposite ends of said slot to thereby limit thedegree of oscillatory movement of said lever in each direction.

3. In an electric snap switch, in combination, a molded insulating basehaving a recess opening to the upper surface thereof, a plurality ofrelatively movable contacts located within said recess, means foreffecting relative movement of' said contacts with a snap action, saidmeans comprising a lever, means for pivotally supporting said .leverrelatively to said base. said last mentioned means comprising a punchedand stamped sheet metal member of substantially inverted channel-shape,the sides of said channel member having anges formed integrallytherewith and adapted to overlie said base, a dat punched plate ofinsulating material interposed between said flanges and said base, aplurality of securing screws extending upwardly from said base andhaving threaded engagement with the upper wall of said inverted channelmember, said insulating plate having recesses formed therein, and saidflanges having bosses formed thereon for engagement with the walls ofsaid recesses to positively insure against spreading of the oppositesides of said channel member upon tightening of said screws.

4. In an electric snap switch, in combination, a molded insulating basehaving a recess opening to the upper surface thereof, a plurality ofrelatively movable contacts located within said recess. means foreffecting relative movement of said contacts with a snap action, saidmeans comprising a flat punched sheet metal lever, means for pivotallysupporting said lever relatively to said base, said last mentioned meanscomprising a punched and stamped sheet metal member of substantiallyinverted channel-shape, the substantially parallel sides of said channelmember having `flanges formed integrally therewith and adapted tooverlie said base, a nat punched plate of insulating material interposedbetween said flanges and said base, a pair of screws extending upwardlyfrom said base and having threaded engagement with the upper wall otsaid channel member, said insulating plate having a plurality of sets ofrelatively small recesses formed therein, said iianges each having a setof correspondingly shaped bosses formed on the lower surface thereof forengagement with the walls of said recesses to positively insure againstspreading of the opposite sides of said channel member upon tighteningof said screws, said member having a slot formed in the upper portionthereof to accommodate said lever, said lever and the sides of saidmember having alined pivot openings formed therein, a pivot pin having aportion of relatively small diameter and a portion of relatively largediameter with a shoulder therebetween, said pin being freely insertableendwise through said openings to provide for engagement of said shoulderwith one side of said lever, and a ferrule slidable onto the smalldiameter portion of said pin into engagement with the other side of saidlever, the outer end of said small diameter portion being upset toretain said fer-rule in clamping engagement with said last mentionedside of said lever.

5. In an electric snap switch, in combination, a molded insulating basehaving a recess opening Vto the upper surface thereof, a plurality ofstationary and movable contacts located within said recess, means foreffecting movement of said movable contacts with a snap action. saidmeans comprising a dat punched sheet metal lever, means for pivotallysupporting said lever relatively to said base, said last mentioned meanscomprising a punched and stamped sheet metal member of substantiallyinverted channel-shape. said member having a slot formed in the upperportion thereof to accommodate said lever, said lever and the sides ofsaid member having alined pivot openings formed therein, a pivot pinhaving a portion of relatively small diameter and a portion ofrelatively large diameter with a shoulder auras?? therebetween, said pinbeing freely insertable endwise through said openings to provide forengagement of said shoulder with one side of said lever, a ferruleslidable onto the small diameter 5 portion of said pin into engagementwith the other side of said lever, the outer end of said small diameterportion being upset to retain said ferrule in clamping engagement withsaid last mentioned side of said lever, said large diameter l portion ofsaid pin and said ferrule each having a good bearing fit within thepivot openings in the sides of said metal member whereby wobbling ofsaid lever is prevented, a plurality of wiring terminal members eachhaving a portion thereof l secured to one of said stationary contactsand to said base in a plane oii'set downwardly from the upper surface ofthe latter, said terminal members each having a portion bent downwardlyat substantially right angles to the first mentioned portions thereof tolie against an end wall of said base, wiring terminal screws carried bysaid downwardly bent portions, a flat punched plate of insulatingmaterial underlying said base and restrained against movement relativelyto the latter 3 in a given plane, said plate having a plurality ofopenings formed therein to provide for upward insertion of wire ends forclamping thereof by the heads of said screws, and the walls of saidopenings acting as snubbing shoulders over which the wires may be bent,for the purpose set forth. 6. In an electric snap switch adapted for endwiring, in combination, a molded insulating base having a recess openingto the upper surface thereof, a plurality of sets of stationary and mov-35 able contacts located within said recess, wiring terminal membershaving fiat portions thereof secured to the stationary contacts in aplane parallel with and spaced downwardly from the upper surface of saidbase, said wiring terminal members having portions thereof bentdownwardly at right angles to the portions thereof aforementioned,Wiring terminal screws having threaded engagement with said downwardlybent portions, said base having means associated therewith to preventoutward displacement of said downwardly bent portions in the event of anoutward pull upon the latter, actuating means for said switch comprisinga at punched sheet metal lever, means for pivotally supporting saidlever relatively to said base, said last mentioned means comprising ametal member of substantially inverted channel-shape, said lastmentioned member having integral flanges adapted to overlie said base, afiat plate of insulating material interposed between said flanges andsaid base, a plurality of screws extending upwardly from said base andhaving threaded engagement with the upper wall of said channel member,said insulating plate and said flanges having cooperating shouldersformed thereon to positively insure against spreading of the oppositesides of said channel member upon tightening of said screws, saidchannel member having a slot formed in the upper wall thereof to accom-65 modate said lever, said lever and said channel member having alinedpivot openings formed therein, a pivot pin having a portion ofrelatively small diameter and a portion of relatively large m diameterwith a shoulder therebetween, said pin being insertable through saidalined openings to provide for engagement of said shoulder with one sideof said lever, and a metal ferrule slidable onto the small diameterportion of said pin into 75 engagement with the other side of saidlever,

the outer end of said small diameter portion being upset to retain saidferrule in position.

'1. In an electric snap switch adapted for end wiring, in combination, amolded insulating base having a recess opening to the upper surfacethereof, a plurality of sets of stationary and movable contacts locatedwithin said recess, a plurality of wiring terminal members having flatportions secured to the respective stationary contacts and to said basein a plane offset downwardly from the upper surface of the latter, saidterminal members having portions bent downwardly at substantially rightangles to said fiat portions thereof, said base having pairs of lateralgrooves formed therein to provide for downward insertion of the sideedges of said downwardly bent portions, whereby the latter arerestrained against displacement in either direction out of the normalplanes thereof respectively, said downwardly bent portions b'eing formedto provide for attachment of circuit wires thereto. means for effectingmovement of said movable contacts in opposite directions respectivelywith a snap action, said means comprising a lever, means for pivotallysupporting said lever relatively to said base, said last mentioned meanscomprising a punched and stamped sheet metal member of substantiallyinverted channel-shape, said channel member having longitudinallyextending langes formed integrally therewith and adapted to overlie saidbase, a fiat plate oi' insulating material interposed between saidflanges and said base, a plurality of screws extending upwardly fromsaid base and engaged with the upper wall of said channel member, saidinsulating plate and said flanges having cooperating shoulders formedintegrally therewith to restrain the opposite sides of said channelmember against spreading as an incident to tightening of said screws.

8. In an electric snap switch adapted for end wiring, in combination, amolded insulating base having a recess opening to the upper surfacethereof, said base having ledges offset downwardly from the uppersurface thereof, a plurality of resilient contacts having portionsthereof superimposed upon the respective ledges, a corresponding numberof wiring terminal members having fiat portions thereof superimposedupon said ledges and rigidly secured thereto in clamping engagement withthe respective contacts, said Wiring terminal members having portionsthereof extending downwardlyvat substantially right angles to said fiatportions, said base `having pairs of spaced downwardly extending groovesformed therein, the grooves of each pair opening toward each other torespectively receive the downwardly extending lateral edge portions ofone of said terminal members, whereby said downwardly extending portionsare engaged with the walls of said pairs of grooves to substantiallyrelieve bending strains tending to move the same inwardly or outwardlywith respect to said base, said downwardly extending portions havingtapped openings formed therein, and binding screws the shanks of whichhave threaded engagement with said tapped openings, said base havingrecesses to accommodate the Shanks of said binding screws.

9. In an electric snap switch, in combination, a molded insulating basehaving a recess opening to the upper surface thereof, a plurality ofrelatively movable contacts located Within said recess, means foreffecting relative movement of the above numbered patent r first lcolumn, line 46, for first column, Patent should be read with these corform to the record of the case in th 10 between said flanges and saidbase. a plurality of securing members extending through said base andengaged with the upper wall of said inverted channel member, saidinsulating plate having shoulders formed thereon, and said flangeshaving shoulders formed thereon for cooperation with said firstmentioned shoulders to positively insure against spreading of theopposite sides ot said channel member upon tightening of said securingmembers.

GEORGE J. MEUER.

CERTIFICATE OF CORRECTION.

Patent No. 2,077,577.

April 2o, 1937.

GEORGE J. MEUER.

It is hereby certified that error appears in the printed specificationequiring correction as follows: the word "electrical" line '7, for"yellow" reed hollow; and that the Said Letters reotions therein thatthe s e Patent Office.

this 5th day of October, A. D. 1937.

Signed and sealed (Seal) Page 1, read electric; page 2,

Henry Van Arsdale Acting Commissioner of Patents.

aille may 00nof the above numbered patent r first l column, line 46, forfirst column, Patent should be read with these cor form to the record ofthe case in th 10 between said flanges and said base. a plurality ofsecuring members extending through said base and engaged with the upperwall of said inverted channel member, said insulating plate havingshoulders formed thereon, and said flanges having shoulders formedthereon for cooperation with said first mentioned shoulders topositively insure against spreading of the opposite sides ot saidchannel member upon tightening of said securing members.

GEORGE J. MEUER.

CERTIFICATE OF CORRECTION.

Patent No. 2,077,577.

April 2o, 1937.

GEORGE J. MEUER.

It is hereby certified that error appears in the printed specificationequiring correction as follows: the word "electrical" line '7, for"yellow" reed hollow; and that the Said Letters reotions therein thatthe s e Patent Office.

this 5th day of October, A. D. 1937.

Signed and sealed (Seal) Page 1, read electric; page 2,

Henry Van Arsdale Acting Commissioner of Patents.

aille may 00n-

